Rachel Uchitel, Tiger Woods' former mistress, reportedly is undergoing major brain surgery to correct Chiari malformations, a condition in which the cerebellum and brain stem are pushed downward into the upper spinal canal. Photo Credit: Getty Images / Frazer Harrison

Tiger Woods' former mistress, Rachel Uchitel, reportedly is undergoing major brain surgery to correct Chiari malformations, in which the cerebellum and brain stem are pushed downward into the upper spinal canal.

TMZ.com said that the operation will take place in two weeks. The condition is often genetic but can also manifest later in life.